1. Field of the Invention
This invention relates to a video camera apparatus arranged to pick up the images of persons participating in a conference, etc., for example, in a system called a video conference system or the like.
2. Description of the Related Art
Heretofore, the images of persons have been picked up by means of a video conference system under such a condition that is, for example, as shown in FIG. 1. In the case of FIG. 1, participants 101, 102 and 103 in a conference are sitting at a table 100. The conference is assumed to be held between two remotely separated places. A video camera 104 is arranged to be panned to pick up the image of any of the participants who is speaking. Then, a video signal and an audio signal obtained by the video camera are transmitted from one conference place to the corresponding conference place via transmission means (not shown) to be displayed as an image and a voice on a monitor which is disposed at the corresponding conference place.
At the remote corresponding conference place, a video camera is likewise arranged to pick up the images and voices of other participants under a condition similar to that shown in FIG. 1. When a participant speaks at the remote corresponding conference place in reply to the speaker displayed on the monitor, the video camera is panned to pick up the image of the second speaker. Video and audio signals thus obtained are transmitted back to the conference place of the first speaker.
The conventional video conference system which is arranged to pick up images in the above-stated manner, however, has presented the following problems:
a) If the video camera which is in a state of having been zoomed in for a speaker is panned from the speaker to a next speaker, a picture displayed on the monitor too vigorously changes. The vigorous change either hardly enables the participants at the corresponding conference place to see what is going on at that moment or makes it difficult for the camera operator to direct the video camera to the next speaker. However, if the panning operation is slowly performed to avoid this difficulty, the video camera cannot be moved and directed to the next speaker in time for the commencement of the speach he or she is making. PA1 b) Since the participants 101, 102 and 103 in the conference are at different distances l1, l2 and l3 from the video camera 104, the images of the participants are picked up in different shot sizes as shown in FIGS. 2(a), 2(b) and 2(c) when the video camera is panned. PA1 c) The video conference system is generally arranged to pan or tilt the video camera on a motor-operated panhead with the former secured to the latter. However, since the weight of the video camera is imposed on the panhead, the moving speed of the panhead is limited. PA1 d) The problems a), b) and c) mentioned above cause the images to appear unpleasantly for participants on the corresponding side of the conference, i.e., image receiving side, and tend to momentarily confuse them as to the position of the speaker on the transmitting side.
These problems take place also in cases where the video camera must be tilted to pick up the images of vertically aligned participants in a conference.